Reading/writing register using macros in a single line in C

[shaikss]

Hi,

I need a small help.
I want to read/write a register by using C code.
By using pointers, its easy.
How to read/write a register using macros?
Just by using a macro, it has to read/write a value.
You should n't use pointers at all.
Pls help me on this.

 

[sci-3d]

Re: Help in C

It's simple to read/write uC register in C. For the example,

P1 = 0x0001;

This will set Port 1 to 0x0001

Is answer to your question?

 

[shaikss]

Re: Help in C

I will tell u one example.
I want to read a register located at 0xFFFFF00F which contains data 0xFFFF.
Can u pls tell me how to write a C code by simply using macros?
By just defining a macro, it has to read the value from the register.

 

[sci-3d]

Re: Help in C

It depends on what particular C compiler you use. I will refer to SDCC which are used in my work [see my blog]


__sfr __at 0xFFFFF00F Var; /* Define Var address at 0xFFFFF00F */

void main(){
Var = 0xFFFF;
}


You also don't forget to mention what CPU/MCU you are using.

 

[jayavardhan]

Help in C

if u want to read the register use the register name and copy the data into it.

i.e if the register name is P1 and u want to read

take a variable Var1.

Var1=P1.

if you do like that u can read the contents of the register.

if it is port, donot forget to make the port as input port.